Potted elctrical component assembly

ABSTRACT

A potted electrical component assembly in which a component is secured to a device such as a cathode ray tube wherein the deflection yoke is potted to the neck of the cathode ray tube by means of a potted sleeve comprised of a cord encircling the neck of the cathode ray and a plastic potting material which solidifies to secure said deflection yoke to the tube neck positioned within the annular space between the deflection yoke and the neck of the tube. The potted sleeve may be removed by pulling out the cord in the direction of the tube axis which unwinds the cored and tears up the plastic potting material.

United States Patent Oberg et al.

15] 3,663,751 1 1 May 16, 1972 [54] POTTED ELCTRICAL COMPONENT ASSEMBLY [72] Inventors: Albert E. Oberg, Horseheads; Laurence E.

White, Montour Falls, both of NY.

Westinghouse Electric Corporation, Pittsburgh, Pa.

[22] Filed: Apr. 16, I970 [21] Appl.No.: 29,073

[73] Assignee:

[56] References Cited UN lTED STATES PATENTS Cummings; ..264/262 Brown ..335/210 3,504,844 4/1970 Stark 161/406 3,032,678 5/1962 Glaser... ...335/2 10 3,497,843 2/1970 Collie 335/2 1 0 Primary Examiner--Robert L. Grifiin Assistant Examiner-Joseph A. Orsino, Jr. Attorney-F. H. Henson and C. F. Renz [5 7] ABSTRACT A potted electrical component assembly in which a component is secured to a device such as a cathode ray tube wherein the deflection yoke is potted to the neck of the cathode ray tube by means of a potted sleeve comprised of a cord encircling the neck of the cathode ray and a plastic potting material which solidifies to secure said deflection yoke to the tube neck positioned within the annular space between the deflection yoke and the neck of the tube. The potted sleeve may be removed by pulling out the cord in the direction of the tube axis which unwinds the cored and tears up the plastic potting material.

4 Claims,l Drawing Figure Patented May 16, 1972 3,663,751

WITNESSES INVENTOR fill); q A\ 4 Albert E. Oberg w gurence E. Whi

3 v v; 1/ r 3 i :JX i

ATTORNEYCD BACKGROUND OF THE INVENTION This invention relates in general to a method and a product as a result thereof for securing an electrical component to another component to provide a unitary structure and yet also provide means for separation of the components without destruction of the components. One particular application of the invention is in certain cathode ray tube applications wherein magnetic focus and deflection elements or components may be assembled about the neck portion of the cathode ray tube. It is essential in this application that the electron beam controlling elements be positioned very precisely and very rigidly relative to the cathode ray tube for optimum performance. It is also essential that the electron beam be shielded from stray magnetic fields including that of the earth.

In the past, it has been the practice to utilize a magnetic shield as a frame to which all the other components including the cathode ray tube are attached. Relatively expensive adjusting and holding fixtures become an integral part of each package so assembled. The attachmentof the components directly to the cathode ray tube by. means of a suitable potting material such as RTV silicone rubber would make holding fixtures unnecessary and would make positioning fixtures reusable by removing them as soon as the potting material has solidified. This latter method has been used only a very few times because of the extreme difficulty in separating the parts in the event that salvage becomes necessary. It is accordingly an object of this invention to provide a simple and economical means for removing components potted directly to another component.

SUMMARY OF THE INVENTION DESCRIPTION OF THE DRAWING For a better understanding of the invention, reference may be had to the preferred embodiment, exemplary of the invention shown in the drawing a cathode ray tube with a deflection yoke secured thereto.

DESCRIPTION OF THE PREFERRED EMBODIMENT A cathode ray tube is shown in the drawing and includes a face plate portion 12, a neck portion 14, and a flared connecting portion 16. A deflection yoke 18 is mounted about the neck portion 14 and is secured to the neck portion 14 by means of a potting layer 20. The potting layer 20 consists of a plurality of turns 22 of a cord 24 and a suitable potting material 23. The potting material 23 is provided between and about the turns 22 of the cord 24, and filling the space 30 enclosed by the deflection yoke 18.

The deflection yoke 18 is positioned on and secured to the cathode ray tube 10 by means of the potting layer 20. The potting layer 20 is provided by winding a strong small diameter cord of a suitable material such as fine nylon cord or a waxed coarse binder cord. The diameter of the cord should be small enough to provide some clearance between the cord and the deflection yoke 18. The cord 24 may be wound with a slight clearance between adjacent turns 22 to insure adequate contact of the potting material with the glass of the cathode ray tube neck 14. After the cord 24 is wound about the glass neck 14 the deflection yoke 18 is positioned about the neck portion 14 and provides the annular space 30 with the spacing between the neck 14 and the deflection yoke 18 being about 0.050 inch. The deflection yoke 18 may be held in a proper position upon the cathode ray tube 10 by means of suitable holding fixtures. A suitable potting material 23 is then flowed into the annular cavity 30 and a suitable material is RTV silicone rubber. This material is liquid and flows between and about the turns 22 of the cord 24 so as to completely fill the region 30 and on solidification securely positions and holds the deflection yoke 18 on the neck portion 14 of the cathode ray tube 10.

If it becomes necessary to remove the deflection yoke 18, this is accomplished simply by pulling on the end 25 of the cord 24 in the direction of the tube axis which unwinds the cord 24 and tears out the potting material 30 in long threads. The presence of the cord 24 provides further benefit in the unitary assembly in providing a layer of substantially compressible material between the deflection yoke and the tube 10 which can absorb some of the stresses created in environmental operation due to exposure of the assembly to extremely low temperatures and etc.

Various modifications may be made within the spirit of the invention and it is obvious that the method described applies to a large number of potting applications where the inside component is nearly cylindrical or where clearance permits insertion of a cylindrical potting sleeve between the components.

We claim:

1. Man electrical device, an inner tubular member and an outer tubular member defining an annular space therebetween, said annular space filled with a cord wound about said inner tubular member and a filling of plastic material filling the remaining portion of said annular space and positioning and securing said outer tubular member with respect to said inner tubular member, said filling of a tearable plastic material so that when said cord is pulled the cord will tear out said filling of plastic material.

2. An electronic tube system comprising evacuated envelope, a control element positioned exterior of said envelope and surrounding at least a portion of said envelope, potting provided between said control element and the exterior surface of said envelope, said potting means comprising a cord wrapped about said envelope with tearable potting material positioned about said turns and securing said control element to said envelope, said cord adapted to be removed and thereby substantially remove enough of said potting means to permit removal of the control element from said envelope without damage either to the envelope or the control element.

3. The system in claim 2 in which said cord extends beyond said potting material.

4. The method of securing and providing ready removal of a component mounted about the neck of a cathode ray tube comprising the steps of wrapping a cord about the tubular neck of the cathode ray tube, positioning an annular control member about said neck portion and said cord, filling the annular region defined between said annular control member and said neck portion with a liquid potting material which on solidification is tearable and secures said annular control member to the tubular neck member with a portion of said cord exposed to permit removal of said potting material by pulling upon said cord. 

1. In an electrical device, an inner tubular member and an outer tubular member defining an annular space therebetween, said annular space filled with a cord wound about said inner tubular member and a filling of plastic material filling the remaining portion of said annular space and positioning and securing said outer tubular member with respect to said inner tubular member, said filling of a tearable plastic material so that when said cord is pulled the cord will tear out said filling of plastic material.
 2. An electronic tube system comprising evacuated envelope, a control element positioned exterior of said envelope and surrounding at least a portion of said envelope, potting provided between said control element and the exterior surface of said envelope, said potting means comprising a cord wrapped about said envelope with tearable potting material positioned about said turns and securing said control element to said envelope, said cord adapted to be removed and thereby substantially remove enough of said potting means to permit removal of the control element from said envelope without damage either to the envelope or the control element.
 3. The system in claim 2 in which said cord extends beyond said potting material.
 4. The method of securing and providing ready removal of a component mounted about the neck of a cathode ray tube comprising the steps of wrapping a cord about the tubular neck of the cathode ray tube, positioning an annular control member about said neck portion and said cord, filling the annular region defined between said annular control member and said neCk portion with a liquid potting material which on solidification is tearable and secures said annular control member to the tubular neck member with a portion of said cord exposed to permit removal of said potting material by pulling upon said cord. 